Improved contact breaker assemblies for use in internal combustion engine ignition systems

ABSTRACT

A contact breaker assembly for use in an ignition distributor for an internal combustion engine ignition system includes a plate carrying a fixed contact. A movable contact is mounted on an insulating heel which is pivotable for a movement in a direction to move the movable contact into and out of engagement with the fixed contact. A leaf spring secured at one end to the heel urges the heel to pivot in a direction to engage the movable contact with the fixed contact. The end of the leaf spring remote from the heel is anchored with respect to the plate, and the spring constitutes part of a conductive path to the movable contact. Said other end of the spring is fixed relative to the plate by means of an insulating block which is carried by the plate. The block is shaped to receive said other end of the leaf spring, and is also shaped to receive a conductive terminal in engagement with the leaf spring. A clamping screw is provided for clamping the terminal in engagement with the block and the leaf spring, so that the movable contact is electrically connected to the terminal through the leaf spring. The clamping screw clamps the end of the leaf spring in position, by virtue of engagement of the terminal and the leaf spring, and the arrangement of the terminal and the clamping screw is such that the terminal can be disengaged from the spring and the block without removing the terminal screw completely from the block.

United States Patet [72] lnventors William Lawrence Fry Ilaughton; Antony Peter Rnyle, Solihull; Peter Darhyshire, Birmingham, all of, England [21] Appl. No. 879,824 [22] Filed Nov. 25, I969 (45] Patented Sept. 7, I971 [73] 'Assignee Joseph Lucas (Industries) Limited Birmingham, England [32] 7 Priority Dee. 6,1968 [3 3] Great Britain [31 1 58154/68 [54] IMPROVED CONTACT BREAKER ASSEMBLIES FOR USE IN INTERNAL COMBUSTION ENGINE IGNITION SYSTEMS 4 Claims, 5 Drawing Figs.

[52] U.S.Cl ..200/166CT, 200/ 19 R [SI] Int. Cl I-I0lh 3/00 [50] Field of Search 200/19 R, 3l R, 166 CT [56] References Cited FOREIGN PATENTS 1,080,213 8/1967 Great Britain 200/19 Primary ExaminerH. 0. Jones Attorney-Holman & Stern ABSTRACT: A contact breaker assembly for use in an ignition distributor for an internal combustion engine ignition system includes a plate carrying a fixed contact. A movable contact is mounted on an insulating heel which is pivotable for a movement in a direction to move the movable contact into and out of engagement with the fixed'contact. A leaf spring secured at one end to the heel urges the heel to pivot in a direction to engage the movable contact with the fixed contact. The end of the leaf spring remote from the heel is anchored with respect to the plate, and the spring constitutes part of a conductive path to the movable contact. Said other end of the spring is fixed relative to the plate by means of an insulating block which is carried by the plate. The block is shaped to receive said other end of the leaf spring, and is also shaped to receive a conductive terminal in engagement with the leaf spring. A clamping screw is provided for clamping the terminal in engagement with the block and the leaf spring, so that the movable contact is electrically connected to the terminal through the leaf spring. The clamping screw clamps the end of the leaf spring in position, by virtue of engagement of the terminal and the leaf spring, and the arrangement of the terminal and the clamping screw is such that the terminal can be disengaged from the spring and the block without removing the terminal screw completely from the block.

IMPROVED CONTACT BREAKER ASSEMBLIES FOR USE IN INTERNAL COMBUSTION ENGINE IGNITION SYSTEMS This invention relates to contact breaker assemblies, for use in road vehicle ignition distributors, of the kind including a plate, a fixed contact carried by said plate, a movable contact movable into and out of engagement with the fixed contact, a leaf spring electrically connected to said movable contact and urging said movable contact towards said fixed contact, and means for anchoring one end of the spring to said plate.

According to the invention, in an assembly of the kind specified said means includes, an insulating member carried by said plate, said insulating member being shaped to receive said one end of the leaf spring and being shaped to receive also a conductive terminal, and further includes clamping means whereby said terminal is clamped in use in contact with said spring so that said movable contact is electrically connected through said spring, to said terminal, the arrangement being such that in use, said terminal can be disengaged from said means without removal of said clamping means.

One example of the invention is illustrated in the accompanying drawings wherein,

FIG. 1 is a plan view of a contact breaker assembly, having a terminal member associated therewith,

FIG. 2 is a view similar to FIG. 1, showing the contact breaker assembly with the terminal member removed,

FIG. 3 is a plan view of part of the assembly shown in FIG. 1, and

FIGS. 4 and 5 are sectional views on the lines 44 and 55 respectively in FIG. 3.

Referring to the drawings, the contact breaker assembly includes an arcuate metal plate 11 carrying an upstanding metal sleeve 12 at one end thereof. Mounted on the sleeve 12 for pivotal movement is an insulating heel member 13, which includes a cam follower portion 14, and which carries a metal shell 15 supporting a movable contact 16. Intermediate its ends, the plate 11 is provided with an upstanding, integral tag 17 which carries a fixed contact 18 engageable by the movable contact 16.

At its end remote from the sleeve 12 the plate 11 is formed with an upstanding, integral flange 33 upon which is mounted an insulating anchorage member 19. The member 19 is moulded in synthetic resin material, and is of generally cuboidal configuration. Extending into the member 19 from the lower face thereof, adjacent one edge thereof is a passage 21 shaped to receive said flange of the plate 11, as an interference fit, the member 19 being supported on the plate 11 by engaging said flange in the passage 21.

Secured to the heel assembly constituted by the heel member 13 and the shell 15 is one end of a conductive leaf spring 20, the leaf spring being electrically connected through the shell 15 to the movable contact 16. The upper face of the member 19 contains a slot 22 adjacent the edge of the member 19 remote from the passage 21. The base of the slot 22 is formed with a transversely extending rib 23 of generally semicircular cross section, and between the slot 22 and the passage 21, the member 19 is formed with a through bore 24, extending between the upper and lower surfaces of the member 19. Upstanding from the upper surface of the member 19 are two pairs of posts 25, 26, the posts 25 being adjacent the comers of the upper surface of the member 19, at the side thereof adjacent the passage 21, and the posts 25 being adjacent the corners of the upper surface of the member 19 on the opposite side of the slot 22 to the posts 25. Moreover, the posts 26 are spaced apart by a distance smaller than the distance by which the posts 25 are spaced apart.

In use, the contact breaker assembly is mounted on the timing plate of an ignition distributor, in such a position that the cam follower portion 14 of the heel 13 is engageable by the cam shaft of the distributor as the cam shaft rotates. The end of the spring 20 remote from the heel 13 is engaged in the slot 22, one edge of the end portion of the spring 20 being formed with a notch within which the rib 23 in the slot 22 is received. A headed screw 27 is received in the bore 24 in screwthreaded engagement therewith, with the head of the screw 27 uppermost. A platelike terminal 28 electrically connected to one terminal of a capacitor is engaged with the member 19. The terminal 28 is formed from metal sheet, and includes a central aperture 29 of diameter larger than the diameter of the head of the screw 27. At one end the terminal 28 is rolled to define a socket receiving one end of a lead 31 through which the terminal is electrically connected to said one terminal of the capacitor, and at its opposite end the terminal 28 is formed witha pair of inclined walls 32 which merge at an apex. The width of the terminal 28 is substantially equal to the distance between the posts 25 on the member 19, and the terminal 28 is engaged with the member 19 by inserting the terminal 28 between the posts 25 and then moving the terminal 28 relative to the member 19 until the edges 32 of the terminal 28 engage the posts 26. It will be appreciated that since the apertures 29 is of larger diameter than the head of the screw 27, the terminal can be engaged with the member 19 without removing the screw 27 completely from the member 19, and then maneuvering the terminal 28 relative to the member 19 until the four posts are engaged by the terminal 28. The arrangement of the member 19 and the terminal 28 is such tat when the terminal 28 is correctly positioned on the member 19, then the aperture 29 in the terminal 28 is not coaxial with the screw 27, the head of the screw 27 overlapping the edge of the aperture 29. Thus, by tightening the screw 27, the head of the screw 27 can be caused to clamp the terminal 28 into engagement with the member 19. The terminal 28 overlies the spring 20, and the depth of the slot 22 inthe member 19 is slightly less than the width of the spring 20, sothat when the terminal 28 is clamped by the screw 27, on the member 19, then the terminal 28 engages the spring 20 thereby electrically connecting the movable contact 16 with the lead 31. In practice, a second terminal member identical with the terminal member 28 but electrically connected to a blade connector on the wall of the distributor casing is engaged with the terminal 28, and both terminals are clamped on the member 19 by the screw 27. Thus the movable contact 16 is electrically connected to said one terminal of the capacitor, and also electrically connected to said connector on the wall of the distributor. The connector on the wall of the distributor is electrically connected to one end of the primary winding of an ignition coil in the ignition circuit of the vehicle and the arrangement is such that in use, opening and closing of the contacts 16, I8 breaks and makes the circuit to the primary winding of the ignition coil to produce high tension pulses in the secondary winding of the ignition coil in known manner. These high tension pulses are distributed to the sparking plugs of the engine of the vehicle in turn in known manner, and the capacitor is electrically connected across the contacts 16, 18 in known manner.

When it is desired to disconnect the terminals from the member 19 it is necessary only to slacken the screw 27, to permit relative movement between the terminals and the member 19. When the screw 27 is slackened the terminals can be maneuvered to a position wherein the apertures in the terminals are coaxial with the head of the screw 27 so that the terminals can be lifted over the head of the screw 27. Thus, the terminal members can be disconnected without the necessity of removing the screw 27 Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A contact breaker assembly for use in an internal combustion engine ignition system including a plate, a fixed contact carried by the plate, and electrically connected thereto, a movable contact insulated from the plate, and movable into and out of engagement with the fixed contact, a conductive leaf spring electrically connected to the movable contact, and urging the movable contact towards the fixed contact, and an insulating member for anchoring one end of the spring to the plate, the insulating member being carried by the plate, and

shaped to receive one end of the spring, the insulating member further being shaped to receive a conductive terminal, and the assembly further including clamping means whereby the terminal is clamped in use in contact with said spring and said insulating member, so that said movable contact is electrically connected through said spring to said terminal, the arrangement of the clamping means being such that said terminal can be disengaged from the insulating member and the spring without removing the clamping means.

2. An assembly as claimed in claim 1 wherein said insulating member is formed with a slot for the reception of said one end of the spring, and said one end of the spring and the wall of the slot include mating surfaces shaped to resist disengagement of said one end of the spring from the insulating member in a longitudinal direction.

3. An assembly as claimed in claim 1 wherein the clamping means includes a screw in threaded engagement with the insulating member, the head of said screw trapping said clamping means in use, against one edge of said end of the spring.

4-. A contact breaker assembly including a plate, a fixed contact carried by the plate and electrically connected thereto, a movable contact insulated from the plate, and movable into and out of engagement with the fixed contact, a leaf spring electrically connected to said movable contact, and urging said movable contact towards said fixed contact, and means for anchoring one end of the spring to said plate, said means including an insulating member carried by said plate and shaped to receive one end of said spring, and a clamping screw in threaded engagement with the insulating member, the assembly further including a conductive terminal in the form of a generally flat blade having an aperture therein of diameter greater than the diameter of the head of the screw, said terminal being clamped, in use, in contact with said one end of said spring by the head of said screw with the shank of said screw passing eccentrically through said aperture in said terminal so that said terminal can be disengaged from the screw by releasing said screw but without removing said screw from the insulating member. 

1. A contact breaker assembly for use in an internal combustion engine ignition system including a plate, a fixed contact carried by the plate, and electrically connected thereto, a movable contact insulated from the plate, and movable into and out of engagement with the fixed contact, a conductive leaf spring electrically connected to the movable contact, and urging the movable contact towards the fixed contact, and an insulating member for anchoring one end of the spring to the plate, the insulating member being carried by the plate, and shaped to receive one end of the spring, the insulating member further being shaped to receive a conductive terminal, and the assembly further including clamping means whereby the terminal is clamped in use in contact with said spring and said insulating member, so that said movable contact is electrically connected through said spring to said terminal, the arrangement of the clamping means being such that said terminal can be disengaged from the insulating member and the spring without removing the clamping means.
 2. An assembly as claimed in claim 1 wherein said insulating member is formed with a slot for the reception of said one end of the spring, and said one end of the spring and the wall of the slot include mating surfaces shaped to resist disengagement of said one end of the spring from the insulating member in a longitudinal direction.
 3. An assembly as claimed in claim 1 wherein the clamping means includes a screw in threaded engagement with the insulating member, the head of said screw trapping said clamping means in use, against one edge of said end of the spring.
 4. A contact breaker assembly including a plate, a fixed contact carried by the plate and electrically connected thereto, a movable contact insulated from the plate, and movable into and out of engagement with the fixed contact, a leaf spring electrically connected to said movable contact, and urging said movable contact towards said fixed contact, and means for anchoring one end of the spring to said plate, said means including an insulating member carried by said plate and shaped to receive one end of said spring, and a clamping screw in threaded engagement with the insulating member, the assembly further including a conductive terminal in the form of a generally flat blade having an aperture therein of diameter greater than the diameter of the head of the screw, said terminal being clamped, in use, in contact with said one end of said spring by the head of said screw with the shank of said screw passing eccentrically through said aperture in said terminal so that said terminal can be disengaged from the screw by releasing said screw but without removing said screw from the insulating member. 